The husband-and-wife owners of a Langley Park liquor store who are linked to a sweeping corruption probe in Prince George's County pleaded not guilty Tuesday in federal court, and the wife was released on home detention as she awaits trial.

Amrick S. Melhi, 51, and his wife, Ravinder K. Melhi, 49, are charged with participating in a scheme to distribute black-market alcohol and cigarettes.

But federal prosecutors have said in court that there also is evidence that the couple bribed public officials in return for favors. They have not been charged with bribery, and prosecutors have not said what officials were allegedly involved.

The case against the Melhis is part of a far-reaching criminal investigation in Prince George's that became public last month when federal agents arrested County Executive Jack B. Johnson (D) and his wife, Leslie, officials said.

The Johnsons are accused of evidence tampering in connection with a probe into whether Jack Johnson took bribes from a developer. They were arrested Nov. 12 after Leslie Johnson allegedly flushed a $100,000 check from an unnamed developer down the toilet at her husband's direction.

The Melhis, of Clarksville, own several liquor stores, including Tick Tock Liquor and Restaurant in Langley Park. They are accused of paying police officers to guard the transportation of untaxed cigarettes and alcohol in Maryland and Virginia.

Prosecutors initially sought to have the Melhis detained pending trial, saying that they traveled frequently to their native India and presented a flight risk. But during a routine hearing Tuesday in U.S. District Court in Greenbelt, Assistant U.S. Attorney James A. Crowell said the government would agree to have Ravinder Melhi released under strict monitoring.

Magistrate Judge Jillyn K. Schulze ordered that Ravinder Melhi can return to her home, where she will be subject to electronic monitoring. Melhi may leave only to see her lawyers or to attend court hearings or medical appointments, Schulze said. Other than paying the mortgage, she cannot make any payment of more than $1,000.

Amrick Melhi continues to be detained awaiting trial.

Dozens of supporters from the Sikh community came to support the couple, filling the courtroom to overflowing. About 200 friends and others signed a petition noting that the couple has lived in the United States for more than 30 years and raised three children.

"They are very well-respected people in our community," said Ajit Dhaliwal, who came to support the couple. "They have lived here for 30 years. Nobody leaves this country when they have kids here."

Prosecutors have said that FBI wiretaps captured conversations in which Amrik Melhi talked to public officials about paying bribes in exchange for favors. The Melhis also have been recorded talking to each other about paying off public officials, officials said.